There are various applications in the semiconductor industry where two substrates in the form of flat panels have to be bonded together. Typically, at least one of the panels would be made of glass. For instance, for touch-screen display panels, two glass panels may have to be bonded together. Another common application is where a protective glass layer is bonded onto a semiconductor wafer in the making of solar panels. An adhesive such as epoxy is typically used to seal the two substrate panels together for downstream processing.
Until now, most substrate bonding machines for conducting substrate-bonding processes are at best semi-automatic in that the loading and unloading of panels are handled manually even if the actual bonding operation is automated. In order to bond two substrates together, an operator is required to load a pair of substrates one at a time into the substrate bonding machine. The machine will perform the bonding process automatically, which typically includes providing an adhesive substance onto a mating surface of one of the substrates, bonding the other substrate onto the mating surface of the first-mentioned substrate and then curing the adhesive. Lastly, the bonded substrates will be manually offloaded and removed from the panel-bonding machine. The panel-bonding machine may not be able to perform bonding during such manual loading and unloading, thereby interrupting the production process and adversely affecting the throughput.
In order to increase the throughput, one approach is to add extra substrate bonding machine lines as illustrated in FIG. 1, which is a schematic layout of a prior art bonding apparatus 100 comprising multiple substrate bonding machines. The machines are arranged next to each other in a row. Each machine comprises a work station 102 where a pair of substrates 104, 104′ is bonded together using an adhesive, such as epoxy. The substrates 104, 104′ are manually loaded onto a substrates supply device 106, which then feeds the substrates 104, 104′ to an input feeder 108 of the work station. After bonding, the bonded substrates, in the form of laminated substrates 110, are individually offloaded from the work station 102. Therefore, loading of substrates 104, 104′ occur at multiple locations to feed the substrates 104, 104′ in parallel into the work stations 102, and offloading of laminated substrates 110 also occurs at multiple locations in parallel.
Using this approach, besides the increase in cost, more space is required to accommodate the extra transport systems of all the machines. Further, extra manpower is required for loading and unloading the substrates at the multiple onloading and offloading locations of the different machines.